An Evaluation method of reflectance spectra to be obtained by Hayabusa2 Near-Infrared Spectrometer (NIRS3) based on laboratory measurements of carbonaceous chondrites

Matsuoka, Moe*; Nakamura, Tomoki*; Osawa, Takahito  ; Iwata, Takahiro*; Kitazato, Kohei*; Abe, Masanao*; Nakauchi, Yusuke*; Arai, Takehiko*; Komatsu, Mutsumi*; Hiroi, Takahiro*; Imae, Naoya*; Yamaguchi, Akira*; Kojima, Hideyasu*

We have conducted ground-based performance evaluation tests of the Near-Infrared Spectrometer (NIRS3) onboard Hayabusa2 spacecraft and established a method for evaluating its measured reflectance spectra. Reflectance spectra of nine powdered carbonaceous chondrite samples were measured by both NIRS3 and a FT-IR spectrometer. Since raw data obtained by NIRS3 had considerable spectral distortion caused by systematic offsets in sensitivity of individual pixels, we have established two methods for correcting the NIRS3 data by comparing them with the corresponding FT-IR data. In order to characterize the absorption bands in NIRS3 spectra, the depth of each band component D is defined for each wavelength (m). Reflectance spectra of asteroid Ryugu, the target asteroid of Hayabusa2, to be recorded by the NIRS3 are expected to reveal the characteristics of the surface materials by using the evaluation technique.